Improvement in wood pavement



UNITED STATES PATENT OFFICE.

A. VAN CAMP, OF. WASHINGTON, DISTRICT OF COLUMBIA, AND M. M.

HODGMAN, or sT.

LOUIS, MISSOURI.

IMPROVEMENT IN WOOD PAVEMENT.

Specification forming part of Letters Patent No. 96,849, dated November 16, 1869.

To all whom it may concern: y

Be it known that we, A. VAN CAMP, of Washington city, and District of Columbia, and M. M. HODGMAN, of St. Louis, in the county of St. Louis and State of Missouri, have invented certain new and useful Improvements in Pavements; and we do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawing, and to the letters of reference marked thereon, making part of this specification, in which- Figure 1 is a plan or top view of a pavement laid in accordance with our plan. Fig. 2 is a sectional view, showing the blocks seated in cement. Fig. 3 is a sectional view, showing the blocks secured to a wooden base.

The object of our invention is to produce a combined block and concrete pavement, in which the materials shall be so blended that it shall possess all the advantages, while, at the same time, it will be entirely free from the disadvantages of each. It will be nearly as cheap as wood, and as lasting as concrete, as elastic as the former, and, at the same time, as firm and durable as the latter.

The concrete demanded for such purposes must be of such impenetrable nature as to be entirely unaffected by either heat or cold, no matter how intense the same may be, and also be alike impervious to the frost and rain.

A moments reflection will convince even the most inexperienced observer that blocks cannot be properly laid and cemented together to form a pavement if the concrete used is constantly expanding or contracting by the action either of the atmosphere or the elements.

The concrete embraced in and covered by our patent of July 27, 1869, and also that claimed in our application of even date herewith, practical experience has shown, is admirably adapted for the purpose.

The nature of our invention consists in cutting, on the opposite sides of a suitable block of wood, semi-hexagonal grooves.

The grooves are cut at such relative position on the block that when they are properly set the grooves in the adjacent block shall be directly opposite each other, having their bearing surface in the lower half-section of the block.

The blocks thus prepared are seated in a concrete bed, sufcient space being left between the blocks, say from one to two inches, for the admission of the cement, and to allow of its being freely rammed until the same is thoroughlyr packed.

To enable others skilled in the art to make and use our invention, we will nowproceed to describe its construction and operation.

A A are the blocks, and may be made of any suitable wood, and either rectangular, square, or of any other desired form, their dimensions being about the same as those generally seen in wooden-block pavements. On the opposite sides of these blocks are cut 1ongitudiual semi-hexagonal grooves a a. The form of these grooves a a may, of course, be varied; but we prefer the style shown, as we desire the wedge-shaped bearing-surface it affords for the concrete to embed itself in. is a concrete bed, and is prepared precisely in accordance with the plan stated in our patent of July 27, 1869.

The concrete is poured down in a warm plastic state, and thoroughly rammed with hot tamps and hot rollers.

The bed B being thus prepared, the blocks are seated therein, their grain running vertically, and the warm concrete is poured in and thoroughly rammed. As will be seen by ref- @rence to Fig. 2, this concrete b unites iirmly and permanently with the bed B, and, extending up, lls the grooves a c, and so ou until, in a thoroughly compact state, it is on a line or iiusli with the upper surface of the blocks A A. The concrete b, that is pourel in, is, as it were, molded between the blocks into the form of a reversed cross, (i.) and it so rigidly secures the blocks that it is almost impossible for them to ever split, chip, or otherwise be injured.

The concrete b may be rammed between the blocks by any desired method. We generally use hot tamps, provided with a broad bladeshaped head, the width of the head being a little less than the distance between the blocks. This' distance between the blocks may be regulated at pleasure.

Having thus fully described our invention, In testimony whereof, we have signed our' what We claim therein as new, and desire to names to this specification in the presence of secure by Letters Patent of the United States, two subscribing Witnesses.

is A. VAN CAMP.

The grooved blocks A A, when they are M. M. HODGMAN.

seated and secured in a concrete bed, B, and Witnesses: v

cemented together by concrete b, es shown and EDWIN JAMES,

described. EDM. F. BROWN. 

